It is well known in the art to use fluorine-containing organic compounds as an inert liquid phase in processes to synthesize fluoropolymers. Such processes may be totally non-aqueous as disclosed by Carlson in U.S. Pat. No. 3,528,954, or the fluorine-containing compound may be used in mixture with water. In these mixed-media processes, the water and the non-aqueous component have low mutual solubility and may be present in a wide range of relative concentrations as illustrated, for example, by Gresham et al. in U.S. Pat. No. 3,635,936 and by Kometani et al. in U.S. Pat. No. 3,462,401 and by Adachi et al. in Japanese patent application publication 03-017106. A favored material for this use has been 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113). However, concern about damage in the earth's ozone layer makes it especially desirable to find an alternative to perhaloalkanes containing chlorine for use as a polymerization medium for fluoropolymers.
Certain alternatives are known in the prior art. Carlson in U.S. Pat. No. 3,642,742 mentions perfluorocyclobutane, perfluorocyclohexane, and perfluorodimethyl cyclobutane. Bro in U.S. Pat. No. 2,952,669 illustrated the polymerization of tetrafluoroethylene (TFE) to polytetrafluoroethylene (PTFE) in perfluorotributylamine. There have been subsequent references to perfluorotributylamine and other perfluorotrialkylamines in polymerization of fluorine-containing monomers. These prior-art compounds do not adequately dissolve hydrocarbon monomers, have global warming potential, and/or have not achieved commercial utility.